From M&S’ Cheshire store to Carl Turner’s Slip House, ‘Bridging the Gap’ isn’t easy, writes Hattie Hartman
Two buildings in the news last week highlight what it takes to do effective post-occupancy monitoring. Marks & Spencer released the impressive results of the Technology Strategy Board-funded study of their recent Cheshire store, designed by Aukett Fitzroy Robinson. And the challenges of data collection after one year of occupancy at Carl Turner Architects’ Slip House, this year’s Manser Medal winner, are revealing.
The Cheshire M&S store is a rare case of a building outperforming its design predictions. The use of hempcrete panels and careful detailing for airtightness have resulted in the building using 60 per cent less heating fuel than predicted.
But it was not all smooth sailing. Trouble-shooting during the first year revealed that the biomass boiler was not operating properly due to incompatibility of the wood pellet supply, and that the piping for the rainwater harvesting system had not been installed correctly. Early detection of these problems meant that they could be corrected immediately. It is not surprising to learn that as part of M&S’ Plan A sustainability programme (which started in 2007), every store now has both a maintenance engineer and a regional energy manager, and energy efficiency is rewarded in the store manager’s bonus.
With neither TSB funding nor a maintenance engineer, Carl Turner Architects’ Slip House is a new-build terraced house in Brixton, which is both home and office for the architect. Turner also reports the normal first-year teething problem, and the measures he has taken to address them:
‘The heat pump had a faulty electrical component and operated only sporadically. Some pipework was also installed incorrectly. This took several months of visits from the combined design and installation teams [to resolve].
‘By trial and error, we discovered that if we cycle the heating to one floor at a time using the floor zone programmers, we could cope even on the coldest days. So we heat the ground floor from 6.30 until 10.30, middle floor from 11.30 until 3.30 and the top floor until 10pm. This reflects the way the house is occupied, with office on the ground floor, bedrooms (middle floor) warmed during the day but not too hot at night and the top floor living space cosy in the evenings.’
To overcome the complexity of compiling data from different sources, Carl Turner Architects is currently installing internal and external temperature sensors which will feed data to a spreadsheet and automate the monitoring process.
Whether a 13,750m² retail store or a 192m² terraced house, effective monitoring requires both persistence and trial and error, particularly when new technologies are involved. Architects do not need to become maintenance engineers or energy managers, but to bridge the gap between predicted and actual energy performance, they need to ensure that monitoring is anticipated, planned for and funded early in the life of a project.